Nowadays a whole range of services with security implications are delivered via the Internet. Thus for example it is known to perform banking transactions or payments via the Internet. Online applications, such as online banking or online payment, represent a target for hackers, however, who want to find out the security data of a user and use this to carry out online transactions in the name of the latter. For example, the authentication data of the user are stolen through various techniques such as phishing or use of Trojans, and subsequently employed to make payments.